USB Pen Drives copy speed fast at the beginning, slows down as it goes

shashu1999

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I have an AMD FX 8120 CPU with an ASUS M8 Motherboard and a WD Craviar Black 1TB HDD. I use Windows 7 Ultimate.
Now, I have tried with like around 10 USB 2.0 Pen Drives and I have to expect atleast 20-25 MBPS copy speed at the least. But what happens is that I am now copying a 1.4GB ISO file from my primary partition of my HDD with NO background programs running, using this software called Tera-Copy (I hv even tried copying using the Windows Copying tool, but same results) and I get aroung 81MBPS till 40% of the file is copied and then I get really low speed like 5MBPS. I have even tried with other files, other pen drives. But the thing is I get superb speeds in the beginning and the ending is really slow.

PEN DRIVES TRIED : HP, SanDisk and Transcend brand's different sized pen drives
Please help me
Thanks
 
Solution
Thanks for replying.

What I said is not entirely accurate but you get the drift of it.
I think that Windows 8 streams the information directly to the input file rather than spooling the information first. The problem with that would be if any interruption occurred like a shut down, the input file and the output file would both be corrupted and you lose the use of both files. At least with spooling, the output file is closed when the spool file is in use and is being sent to the input file.

Source file is output, target file is input, just to clarify things.

I had to copy nearly 200gb of data from an external hdd to the Pc (Windows 7 x64) and it took nearly 4 hours, the final closing of the session took about 12 minutes. Next time, I...

AutomaticCoding

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Technically you still are getting your minimum 25MBps:-
https://www.google.com/search?q=((81*4)%2B(5*6))%2F10

Just sayin', you really shouldn't be complaining that you're not reaching what you are reaching. As for the drive, try reducing the other variables first of all. Either copy data directly off a RamDisk or just generate the data (Great command in linux would be dd if=/dev/zero of=/dev/sdX), compare those results.

Anyway, can I just confirm that the same issue is happening over ten different flash drives? All different models? Try a difference PC for starters, that sounds pretty dodgy.

EDIT:- Oh, and try copying the iso itself somewhere else, or just read from it. How long does that take? If it's over ten different flash drives, sounds more like a problem with the source point than the destination point.
 

TenPc

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Try the Send To option, right-click the file and select Send To (device), it might be a quicker copy.

It also depends on how many other usb ports are in use and whether the port you are using is the same USB type as the device. If the device is USB 3.0 type and your port isonly USB 2.0 then expect a slower speed.

If your motherboard does not support usb3.0 only usb 2.0 then you only get about 2 or 3 ports that are USB 2.0 and the others are only USB 1.1
but you would receive a message from Windows Os stating that you have plugged in a usb device that is either low poered or high powered.

Also, consider how much free space you have on the pen drive, whether you have copied data previously and deleted many tmes, and whether you have formatted the pen drive way too many times, as formatting creates "wear and ter" and deleting doesn't really delete anything, it sets the "deleted" file to be overwritten and "hidden" to allow UNDELETE of deleted files.

A new pendrive receives data quicker and more efficently than a used pen drive.


I forgot to mention that Windows 7 x32 or x64 uses a background service for its copy mode, you will see a slow performance towards the end of its run, a copy to another device orOS requires the use of temp files, it's never just a straight movement from one device to another.

When you start the copy, you should see a message stating that the copy is being processed. The iso file has to be read from the top to the end of the file before it actually goes to the other device. The last trickle of the copy process is actually the file being closed and the temp file being erased. It can add an extra ten minutes to the copy process.

You should try copying 40gb of data to another hdd, it takes about 2 hours on a slow PC. with only 2gb of ram.
 

shashu1999

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I have tried using ten different pen drives in my computer. I have 6 USB 2.0 Ports and 2 USB 3.0 Ports.
All my devices are 2.0

And AutomaticCoding, I am getting not 31MBPS, I just get 5MBPS at the later end of the copying stage. I get around 80MBPS at the first quarter of the coyping. The Mystery is that, WHY does the speed drop suddenly. When I get 80MBPS, the speed starts dropping until it is around 5MBPS. And another problem is that, it doesnt matter what I copy, where from I copy, the copying stops at the last MB and the green progress bar starts moving for around 2-3MIN, then the copying is complete. When the 99% of the copying takes some time, the last 1% of the copying takes hell a lot of time. Thats not what I am able to solve.

And TenPC, I have even tried the Send To option.
Thanks
 

TenPc

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This is an old thread but I have to (must) add the reason for the drop in speed. I can't explain it technically so bear with me and hopefully it is understood to some degree.

The system spools the information to be copied before sending it to the other end wihch is why you get the 80mbps but at the end of the spooling, Windows needs to delete the temp (spooled) file, sometimes you might see in the copy dialog zero volume being transferred, and the lower speed of 5mbps is just the recovery status. It can add up to about 2 minutes of copy time making you think that something is amiss but it's just Windows feeling "exhausted" from the action just taken place.
 

shashu1999

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I get it... I did quite a bit of research and figured out that Windows doesn't really estimate the copy speed properly..

Anyways after some comparison, I just found out that Windows 8 does copy files a lot faster that what Windows 7 does on the same hard drive.. So is there any update which Microsoft will be releasing to fix these type of issues?
 

TenPc

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Thanks for replying.

What I said is not entirely accurate but you get the drift of it.
I think that Windows 8 streams the information directly to the input file rather than spooling the information first. The problem with that would be if any interruption occurred like a shut down, the input file and the output file would both be corrupted and you lose the use of both files. At least with spooling, the output file is closed when the spool file is in use and is being sent to the input file.

Source file is output, target file is input, just to clarify things.

I had to copy nearly 200gb of data from an external hdd to the Pc (Windows 7 x64) and it took nearly 4 hours, the final closing of the session took about 12 minutes. Next time, I think I'd rather do only about 20gb at a time, it would be quicker even though somewhat bothersome to do.

When the data being copied gets close towards the end point, it has to then re-calculate the volume left over, then it has to close the input file then remove the temp file then close the output file.

There is no fix because there is no issue, it's just the way it is done.
 
Solution

jun25

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i have the same issue. when i use a fat32 formatted usb drive, no problem. but when i use ntfs formatted usb drive, copying slows down in the middle and more so in the end.
 

GeorgeBoles

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Before I start a new thread, is this the same logic for copying to a NAS or another computer on my network?

Copying 2GB or random files takes approx 40+ minutes.
The same 2GB files zipped to 1.5 GB SINGLE file takes about 3 minutes!
The 2GB random files START at the same speed and slow down progressively through the copy, grinding to a near halt near the end of the copy.

Also looking at the network utilization in Task Manager, the 1.5GB file runs at a steady speed, but the multiple files start at the same steady speed and then degenerate to a series of smaller and less exciting blips through the whole copy ...

This is FROM a Windows 7 computer to:
a) another Windows 7 computer,
b) mac mini
c) NAS box.

On the other hand, when I copy from:
a) mac mini
b)NAS

to either of my Windows 7 computers, the file transfer times are about the same (roughly proportional to the total file sizes - just slightly slower per GB for the multiple file copy).

I understand from other reading that the same thing applies copying Windows 7 to Windows XP (slow) but XP to 7 is fast.

I have tried EVERY fix found on the internet: none work.

Why is this?
Seems dumb to me that XP and mac mini are 20 times faster than Windows 7!

Deserves a new thread?

Regards,
George.